The present study investigated the effects of varying protein source combinations and feeding strategies on the growth,health and organoleptic quality of the large yellow croaker(Larimichthys crocea).Three iso-nitroge...The present study investigated the effects of varying protein source combinations and feeding strategies on the growth,health and organoleptic quality of the large yellow croaker(Larimichthys crocea).Three iso-nitrogenous and iso-lipidic diets were formulated.The control diet was made with 62%fish meal(FM).The other two experimental diets were formulated by replacing 45%FM with 22.5%mealworm(TM)and 22.5%cottonseed protein concentrate(CPC),or with 22.5%TM and 22.5%Clostridium autoethanogenum protein(CAP),respectively.The three kinds of diet were named as A1,A2 and A3,respectively.Five groups of large yellow croaker were fed with two different strategies:the first three groups were continuously fed with A1,A2 and A3 diets,respectively.The fourth group was alternately fed with A1 and A2 diet every 5 days.The fifth group was alternately fed with A1 and A3diet every 5 days.The five groups were named D1,D2,D3,D1-2 and D1-3,respectively.Results showed that D2 and D3 groups exhibited significantly lower weight gain rate(WGR)and higher feed conversion ratios(FCR)compared to the D1 group.The D1-2 and D1-3 groups exhibited improved WGR and significantly reduced FCR compared to the D2 and D3 groups.The A2 and A3 diets significantly suppressed digestive enzymes'activities compared to A1,whereas alternate-feeding groups significantly enhanced the enzyme activities.Compared to the D1 group,D2 and D3 groups significantly downregulated mRNA expression levels of intestinal antiinflammatory cytokines and upregulated the expression of pro-inflammatory mediators.The anti-inflammatory abilities in the D1-2and D1-3 groups were significantly higher than those in the D2 and D3 groups.Additionally,diets containing TM+CAP and TM+CPC protein sources enhanced ventral redness and yellowness indices.Considering the growth,digestion,immunity and organoleptic quality of large yellow croaker,it is recommended to replace up to 45%of FM with TM+CPC and use an alternate-feeding strategy.展开更多
为探究不同pH值对大黄鱼胚胎发育及初孵仔鱼的影响,将大黄鱼受精卵和初孵仔鱼分别置于pH值为6.5、7.0、7.5、8.0、8.5、9.0的环境中,进行胚胎发育观察和对初孵仔鱼的耐受性分析。结果表明,pH值处于7.0~8.5范围时,大黄鱼受精卵均能完成...为探究不同pH值对大黄鱼胚胎发育及初孵仔鱼的影响,将大黄鱼受精卵和初孵仔鱼分别置于pH值为6.5、7.0、7.5、8.0、8.5、9.0的环境中,进行胚胎发育观察和对初孵仔鱼的耐受性分析。结果表明,pH值处于7.0~8.5范围时,大黄鱼受精卵均能完成胚胎发育全过程,所需时间为22 h 24 min至23 h 37 min。孵化率随着pH值的升高出现先上升后下降的现象。其中,pH=8.0时,大黄鱼的孵化率最高,为(91.10±1.44)%;pH=6.5和pH=9.0时,大黄鱼的受精卵分别发育至原肠早期和胚孔关闭期则停止发育,孵化率为0。大黄鱼初孵仔鱼在不同pH值下的半数死亡时间和全数死亡时间差异显著(P<0.05),半数死亡时间在(46.50±3.23)h至(243.70±7.32)h之间,全数死亡时间在(70.80±3.67)h至(314.60±7.69)h之间,其中,pH=6.5时的仔鱼半数死亡时间与全数死亡时间均与其他试验组有显著差异(P<0.05)。展开更多
基金financially supported by the Key Research and Development Program of Shandong,China(No.2021SFGC0701)。
文摘The present study investigated the effects of varying protein source combinations and feeding strategies on the growth,health and organoleptic quality of the large yellow croaker(Larimichthys crocea).Three iso-nitrogenous and iso-lipidic diets were formulated.The control diet was made with 62%fish meal(FM).The other two experimental diets were formulated by replacing 45%FM with 22.5%mealworm(TM)and 22.5%cottonseed protein concentrate(CPC),or with 22.5%TM and 22.5%Clostridium autoethanogenum protein(CAP),respectively.The three kinds of diet were named as A1,A2 and A3,respectively.Five groups of large yellow croaker were fed with two different strategies:the first three groups were continuously fed with A1,A2 and A3 diets,respectively.The fourth group was alternately fed with A1 and A2 diet every 5 days.The fifth group was alternately fed with A1 and A3diet every 5 days.The five groups were named D1,D2,D3,D1-2 and D1-3,respectively.Results showed that D2 and D3 groups exhibited significantly lower weight gain rate(WGR)and higher feed conversion ratios(FCR)compared to the D1 group.The D1-2 and D1-3 groups exhibited improved WGR and significantly reduced FCR compared to the D2 and D3 groups.The A2 and A3 diets significantly suppressed digestive enzymes'activities compared to A1,whereas alternate-feeding groups significantly enhanced the enzyme activities.Compared to the D1 group,D2 and D3 groups significantly downregulated mRNA expression levels of intestinal antiinflammatory cytokines and upregulated the expression of pro-inflammatory mediators.The anti-inflammatory abilities in the D1-2and D1-3 groups were significantly higher than those in the D2 and D3 groups.Additionally,diets containing TM+CAP and TM+CPC protein sources enhanced ventral redness and yellowness indices.Considering the growth,digestion,immunity and organoleptic quality of large yellow croaker,it is recommended to replace up to 45%of FM with TM+CPC and use an alternate-feeding strategy.
文摘为探究不同pH值对大黄鱼胚胎发育及初孵仔鱼的影响,将大黄鱼受精卵和初孵仔鱼分别置于pH值为6.5、7.0、7.5、8.0、8.5、9.0的环境中,进行胚胎发育观察和对初孵仔鱼的耐受性分析。结果表明,pH值处于7.0~8.5范围时,大黄鱼受精卵均能完成胚胎发育全过程,所需时间为22 h 24 min至23 h 37 min。孵化率随着pH值的升高出现先上升后下降的现象。其中,pH=8.0时,大黄鱼的孵化率最高,为(91.10±1.44)%;pH=6.5和pH=9.0时,大黄鱼的受精卵分别发育至原肠早期和胚孔关闭期则停止发育,孵化率为0。大黄鱼初孵仔鱼在不同pH值下的半数死亡时间和全数死亡时间差异显著(P<0.05),半数死亡时间在(46.50±3.23)h至(243.70±7.32)h之间,全数死亡时间在(70.80±3.67)h至(314.60±7.69)h之间,其中,pH=6.5时的仔鱼半数死亡时间与全数死亡时间均与其他试验组有显著差异(P<0.05)。
